I'm trying to get my 11 week old puppy (75% APBT/25% Bullmastiff) to pee and poop outside only. I've been using the basic clicker + treat combo as a reward for doing so but he's still having accidents even though I bring him out 6-8 times a day. As a result I've also started to spray him with a water bottle for these accidents.

At eleven weeks your pup is still an infant, he is going to have accidents. Keep throwing him a party and telling him what a superstar he is every time he goes outside where he is supposed to. Eventually he will get it, but if you lose your patience now all he will learn is not to go when you are looking! Potty training is frustrating, I know, it takes a long time. Lilith is eleven months and still decides to pee on the floor every few weeks just to see if it's okay this time.

Look in the training section for lots of other suggestions on potty training. There is a bunch of info already here! Good luck, and try to stay patient!